Modular and adjustable swin fin

ABSTRACT

The present invention extends to apparatuses and methods directed to a modular and adjustable swim fin. Some aspects of the invention include a swim fin having one or more interchangeable fin ribs that facilitate adjustment of flexibility characteristics of the swim fin. For example, interchangeable fin ribs having different flexibility characteristics (e.g., durometer, stiffness, rigidity, or hardness) provide desirable performance when attached to a fin blade of a swim fin. In addition, some aspects of the invention include a fin blade with an adjustable fin split that facilitates use of either a solid fin blade when the adjustable fin split is closed or a split fin blade when the adjustable fin split is open.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims the benefit of U.S. Provisional Patent Application Ser. No. 62/545,679 entitled “Module And Adjustable Swim Fin”, filed Aug. 15, 2017 which is incorporated herein in its entirety.

FIELD OF THE INVENTION

Aspects of the present invention generally relate to aspects of a swim fin. More particularly, aspects of the invention relate to apparatuses and methods directed to a modular and adjustable swim fin.

BACKGROUND

Swim fins, also known as flippers or fins, are finlike accessories typically worn on a user's feet or legs to help propel the user when in water. More specifically, swim fins help facilitate movement through water because human feet are usually unsuitably shaped and too small to provide much thrust. Thus, users often wear swim fins when engaging in various water sports activities, such as swimming, snorkeling, scuba diving, bodysurfing, and bodyboarding, among others. Not surprisingly, numerous swim fins have been designed and developed to be used specifically for each water sport activity. For example, very long and flexible swim fins have been specially designed for scuba diving, whereas shorter and stiffer swim fins have been particularly developed for bodysurfing. As a result, users often need several pairs of different swim fins to effectively participate in multiple water sport activities of their choice.

Swim fins typically have a unitary one-piece design and, as such, are not very versatile. For example, it is often the case that swim fins have a fin blade and foot pocket that are molded together as a single fixed piece. Thus, if a user wants to change the fin blade but keep the foot pocket, or vice versa, then the only option for the user is to obtain an entirely different pair of swim fins. Moreover, swim fins with a unitary one-piece design often exhibit poor durability, as such swim fins can only be as sturdy and robust as their weakest component. As an example, if the foot pocket of a typical one-piece swim fin tears or is otherwise damaged, then oftentimes a user must replace the entire swim fin (or pair of swim fins) rather than simply replace just the broken foot pocket component. Consequently, typical one-piece swim fins are more difficult to maintain and repair.

Typical swim fins also have a fixed stiffness. This further limits the versatility of typical swim fins. For example, swim fins for scuba diving typically have a fixed stiffness that differs substantially from the fixed stiffness of swim fins used for bodysurfing. Consequently, scuba diving swim fins are generally unsuitable for bodysurfing and likewise, bodysurfing swim fins are generally unsuitable for scuba diving. Thus, more generally, swim fins ideally suited for a first application (e.g., scuba diving) cannot normally be adjusted for use in a second application (e.g., bodysurfing). As a result, users who participate in multiple water sport activities oftentimes have numerous swim fin pairs particularly adapted for a specific water sport activity.

Further, typical swim fins have a static fin blade which further limits their versatility. Thus, typical swim fins are usually only ideally suited for certain conditions and cannot be adjusted. For example, typical swim fins often have either a solid fin blade (i.e., a paddle) or a split fin blade (e.g., split along the centerline of the blade), but are not capable of providing the functionality and advantages of both. Solid fin blades may be desirable for certain water sport activities, whereas split fin blades may be desirable for others. Accordingly, users often need various swim fins, some of which have solid fin blades and others that have split fin blades, in order to optimally participate in multiple water sport activities.

BRIEF DESCRIPTION OF THE DRAWINGS

In order to describe the manner in which the above-recited and other advantages and features can be obtained, a more particular description will be rendered by reference to specific implementations thereof which are illustrated in the appended drawings. Understanding that these drawings depict only some implementations and are not therefore to be considered to be limiting of its scope, implementations will be described and explained with additional specificity and detail through the use of the accompanying drawings in which:

FIG. 1A is a perspective view of an example swim fin having a solid fin blade;

FIG. 1B is a perspective view of the solid fin blade of the example swim fin shown in FIG. 1A;

FIG. 1C is a front elevational view of the solid fin blade of the example swim fin shown in FIG. 1A;

FIG. 1D is a rear elevational view of the solid fin blade of the example swim fin shown in FIG. 1A;

FIG. 1E is a right side elevational view of the solid fin blade of the example swim fin shown in FIG. 1A;

FIG. 1F is a left side elevational view of the solid fin blade of the example swim fin shown in FIG. 1A;

FIG. 1G is a top plan view of the solid fin blade of the example swim fin shown in FIG. 1A;

FIG. 1H is a bottom plan view of the solid fin blade of the example swim fin shown in FIG. 1A;

FIG. 2A is a perspective view of an example swim fin having a split fin blade;

FIG. 2B is a perspective view of the split fin blade of the example swim fin shown in FIG. 2A;

FIG. 2C is a front elevational view of the split fin blade of the example swim fin shown in FIG. 2A;

FIG. 2D is a rear elevational view of the split fin blade of the example swim fin shown in FIG. 2A;

FIG. 2E is a right side elevational view of the split fin blade of the example swim fin shown in FIG. 2A;

FIG. 2F is a left side elevational view of the split fin blade of the example swim fin shown in FIG. 2A;

FIG. 2G is a top plan view of the split fin blade of the example swim fin shown in FIG. 2A;

FIG. 2H is a bottom plan view of the split fin blade of the example swim fin shown in FIG. 2A;

FIG. 3A is a perspective view of an example swim fin having an adjustable fin blade;

FIG. 3B is a perspective view of the adjustable fin blade of the example swim fin shown in FIG. 3A;

FIG. 3C is a front elevational view of the adjustable fin blade of the example swim fin shown in FIG. 3A;

FIG. 3D is a rear elevational view of the adjustable fin blade of the example swim fin shown in FIG. 3A;

FIG. 3E is a right side elevational view of the adjustable fin blade of the example swim fin shown in FIG. 3A;

FIG. 3F is a left side elevational view of the adjustable fin blade of the example swim fin shown in FIG. 3A;

FIG. 3G is a top plan view of the adjustable fin blade of the example swim fin shown in FIG. 3A; and

FIG. 3H is a bottom plan view of the adjustable fin blade of the example swim fin shown in FIG. 3A.

DETAILED DESCRIPTION

Aspects of the present invention relate to a modular and adjustable swim fin. More particularly, at least some aspects of the invention relate to a swim fin having one or more interchangeable fin ribs that facilitate adjustment of flexibility characteristics of the swim fin. For example, some aspects of the invention relate to interchangeable fin ribs having different flexibility characteristics (e.g., durometer, stiffness, rigidity, or hardness) which provide desirable performance when attached to a fin blade of a swim fin. In addition, some aspects of the invention relate to a swim fin having a fin blade with an adjustable fin split that facilitates use of either a solid fin blade when the adjustable fin split is closed or a split fin blade when the adjustable fin split is open.

One problem with typical swim fins is that they are not modular and interchangeable. In particular, typical swim fins often have a one-piece design that does not allow a user to swap different components based on the user's particular needs and intended application. Another problem with typical swim fins is that their flexibility is not adjustable. Oftentimes, this is due to the fixed stiffness of typical fin blades. Yet an additional problem with swim fins is the fixed design of fin blades, as typical swim fin blades are static and therefore do not assist a user in changing the fin blades according to the user's specific requirements.

Aspects of the invention address the foregoing problems in various ways. In particular, aspects of the invention provide apparatuses and methods directed to a modular and adjustable swim fin. More specifically, aspects of the invention provide a modular swim fin with interchangeable parts to improve the durability of the swim fin. Accordingly, aspects of the invention allow a user to swap different components of swim fins. Moreover, aspects of the invention provide a swim fin with adjustable stiffness to improve the versatility of the swim fin. Furthermore, aspects of the present invention provide a swim fin with an adjustable fin blade that can serve as both a solid fin blade and a split fin blade, as may be desired by a user.

A. Example Solid Fin Blade

In general, FIG. 1A shows an example of a modular and adjustable swim fin. More specifically, FIG. 1A shows a swim fin 100 that includes a fin blade 110, fin ribs 120 a-120 b, and a foot pocket 130. While FIG. 1 shows that fin blade 110 is a solid fin blade, in other aspects fin blade 110 can include a fin split or adjustable fin split as described in greater detail with respect to FIGS. 2A-2H and 3A-3H.

Additionally, FIG. 1A shows that fin rib 120 a includes a proximal rib portion 121 a having one or more proximal fasteners 122 a and a distal rib portion 123 a having distal fasteners 124 a-125 a. Moreover, as shown by FIG. 1A, the distal rib portion 123 a further includes a rib aperture 126 a. FIG. 1A also illustrates that fin rib 120 b contains the same features as fin rib 120 a, thus it should be appreciated that the features of fin rib 120 a are equally applicable to fin rib 120 b.

Furthermore, as FIG. 1A shows, swim fin 100 includes a fin blade 110 that attaches to fin ribs 120 a-120 b and foot pocket 130. In particular, foot pocket 130 includes a pair of edges that fit between fin blade 110 and the respective proximal rib portions of fin ribs 120 a-120 b (i.e., the pair of edges of foot pocket 130 are sandwiched between fin ribs 120 a-120 b and fin blade 110). Accordingly, in order to fasten together fin blade 110, fin ribs 120 a-120 b, and foot pocket 130, the pair of edges of foot pocket 130 include one or more holes that align with one or more holes on fin blade 110 and one or more holes on the respective proximal rib portions of fin ribs 120 a-120 b. Thus, fin blade 110, fin ribs 120 a-120 b, and foot pocket 130 are secured by one or more proximal fasteners 122 a (e.g., bolts, screws, or other threaded fasteners) that protrude through the holes of fin blade 110, fin ribs 120 a-120 b, and foot pocket 130 to fasten them together. Along similar lines, distal fasteners 124 a-125 a (e.g., bolts, screws, or other threaded fasteners) secure fin blade 110 to the distal rib portion 123 a of fin rib 120 a using one or more aligned holes on fin blade 110 and fin rib 120 a.

Alternatively, in other aspects, fin blade 110, fin ribs 120 a-120 b, and foot pocket 130 can be fastened together by other types of fasteners, such as clips or non-threaded fasteners. For example, clips on fin ribs 120 a-120 b can be used to secure fin blade 110, fin ribs 120 a-120 b, and foot pocket 130 together by clipping onto fin blade 110 and sandwiching the edges of foot pocket 130 between fin blade 110 and fin ribs 120 a-120 b. As another alternative, fasteners on foot pocket 130 can be used to secure fin blade 110, fin ribs 120 a-120 b, and foot pocket 130 together. As an example, foot pocket 130 can include a pair of clips that clip onto fin blade 110 and sandwich the respective fin ribs 120 a-120 b between fin blade 110 and foot pocket 130. As yet another alternative, fasteners on fin blade 110 can be used to secure fin blade 110, fin ribs 120 a-120 b, and foot pocket 130 together. For example, fin blade 110 can include a pair of clips that clip onto fin ribs 120 a-120 b and foot pocket 130, such that the pair of clips sandwiches fin ribs 120 a-120 b between fin blade 110 and the edges of foot pocket 130, or such that the pair of clips sandwiches the edges of foot pocket 130 between fin ribs 120 a-120 b and fin blade 110.

FIG. 1A further illustrates additional aspects of the invention. For example, FIG. 1A shows that foot pocket 130 includes an open toe-open heel design. However, in other aspects, foot pocket 130 can have any other suitable foot pocket design (e.g., full-foot, open toe-full heel, closed toe-open heel, etc.). Additionally, FIG. 1A shows that the distal rib portion 123 a of fin rib 120 a includes a distal rib fastener 125 a spaced inward toward the centerline of fin blade 110. Providing a fastener in such a location on fin blade 110 can provide certain desirable swim fin characteristics related to flexibility and durability (e.g., providing more rigidity towards the centerline of fin blade 110 or reinforcing the attachment of fin blade 110 to distal rib portion 123 a). Along similar lines, FIG. 1A shows that the distal rib portion 123 a of fin rib 120 a further includes rib aperture 126 a, which can also provide certain desirable swim fin characteristics related to flexibility and durability.

Additionally, FIG. 1A shows that fin blade 110, fin ribs 120 a-120 b, and foot pocket 130 can be interchanged for other respective fin blades, fin ribs, and foot pockets offering different characteristics. For example, swim fin 100 can be used with multiple different pairs of fin ribs 120 a-120 b that provide various flexibility characteristics. More specifically, swim fin 100 can be used with a first pair of fin ribs having a first durometer (i.e., stiffness, rigidity, or hardness) which can be interchanged with a second pair of fin ribs having a second durometer, wherein the first durometer differs from than the second durometer (e.g., the first pair of fin ribs is very flexible and the second pair of fin ribs is less flexible and more stiff). Along similar lines, swim fin 100 can be used with a first pair of fin ribs having a first length which can be interchanged with a second pair of fin ribs having a second length, wherein the first length differs from the second length (e.g., the first pair of fin ribs is shorter and provides more flexibility than the second pair of fin ribs which is longer and stiffer). As a further example, swim fin 100 can be used with multiple different foot pockets 130, such as a first foot pocket having an open toe-open heel design which can be interchanged with a second foot pocket having a full foot design. As yet another example, swim fin 100 can be used with multiple different fin blades 110, such as a first fin blade having a solid fin blade which can be interchanged with a second fin blade having a fin split or a third fin blade having an adjustable fin split (e.g., like the fin blades described with respect to FIGS. 2A-2H and 3A-3H described in further detail below).

FIG. 1B shows a perspective view of fin blade 110 of FIG. 1A. More specifically, FIG. 1B shows that in one aspect fin blade 110 includes proximal indentations 117 a-117 b and distal indentations 118 a-118 b. Proximal indentations 117 a-117 b are shaped to receive the edges of foot pocket 130. Similarly, distal indentations 118 a-118 b are shaped to receive the distal rib portions of fin ribs 120 a-120 b. Alternatively, in other aspects where proximal rib portions of fin ribs 120 a-120 b are sandwiched between fin blade 110 and the edges of foot pocket 130, proximal indentations 117 a-117 b can be shaped to receive the proximal rib portions of fin ribs 120 a-120 b.

FIG. 1C shows a front view of fin blade 110 of FIG. 1A. In particular, FIG. 1C shows that in one aspect the top of the distal portion of fin blade 110 is concave and the bottom of fin blade 110 includes distal protrusions 119 a-119 b. Distal protrusions 119 a-119 b also include the holes of fin blade 110 which align with holes on the distal rib portion of fin ribs 120 a-120 b to engage distal fasteners of fin ribs 120 a-120 b (e.g., distal rib fasteners 124 a-125 a for fin rib 120 a and distal protrusion 119 a). Alternatively, in other aspects, distal protrusions 119 a-119 b can be solid (i.e., not include holes for fasteners) to simply provide improved reinforcement to fin blade 110.

FIG. 1D shows a rear view of fin blade 110 of FIG. 1A. More specifically, FIG. 1D shows that proximal indentations 117 a-117 b are deeper than distal indentations 118 a-118 b. The difference in depth between proximal indentations 117 a-117 b and distal indentations 118 a-118 b can provide desirable flexibility characteristics (e.g., a stiffer and more rigid proximal portion of the swim fin as compared to a more flexible distal portion of the swim fin).

FIG. 1E shows a right side view of fin blade 110 of FIG. 1A. In particular, FIG. 1E shows that the bottom right side of fin blade 110 includes distal protrusion 119 b and the proximal portion of fin blade 110 is substantially flat, whereas the distal portion of fin blade 110 slopes upward as a result of the concave shape of the top of the distal portion of fin blade 110. Likewise, FIG. 1F shows a left side view of fin blade 110 of FIG. 1A. More specifically, FIG. 1F shows that the bottom left side of fin blade 110 includes distal protrusion 119 a and the proximal portion of fin blade 110 is substantially flat, whereas the distal portion of fin blade 110 slopes upward as a result of the concave shape of the top of the distal portion of fin blade 110.

FIG. 1G shows a top plan view of fin blade 110 of FIG. 1A. In particular, FIG. 1G shows that fin blade 110 has a curved distal edge and a shape that flares from the proximal end to the distal end of fin blade 110 (i.e., fin blade 110 has a substantially trapezoidal shape that tapers from the distal end to the proximal end of fin blade 110). Additionally, FIG. 1G shows that fin blade 110 includes proximal indentations 117 a-117 b and distal indentations 118 a-118 b which have one or more holes to receive fasteners and are shaped and configured to receive respective fin ribs 120 a-120 b.

FIG. 1H shows a bottom plan view of fin blade 110 of FIG. 1A. More specifically, FIG. 1H shows that the bottom of fin blade 110 includes proximal protrusions 111 a-111 b and distal protrusions 119 a-119 b. Additionally, each proximal protrusion 111 a-111 b includes a proximal indentation, such as proximal indentation 115. Proximal protrusions 111 a-111 b and corresponding proximal indentations, like proximal indentations 115, provide desired support and stiffness to fin blade 110. Moreover, like distal protrusions 119 a-119 b, proximal protrusions 111 a-111 b also include holes of fin blade 110 which align with holes on foot pocket 130 and the proximal rib portion of fin ribs 120 a-120 b to engage proximal fasteners of fin ribs 120 a-120 b. Alternatively, in other aspects, proximal protrusions 111 a-111 b can be solid (i.e., not include holes for fasteners) to simply provide improved reinforcement to fin blade 110. Furthermore, FIG. 1H shows that the proximal end of the bottom of fin blade 110 includes one or more sole treads 113 that provide improved traction for the swim fin.

B. Example Split Fin Blade

In general, FIG. 2A shows another example aspect of a modular and adjustable swim fin. More specifically, FIG. 2A shows a swim fin 200 that includes a fin blade 210, a fin split 212, fin ribs 220 a-220 b, and a foot pocket 230. Fin blade 210 with fin split 212 (located along the centerline of fin blade 210) provides desirable performance for certain water sport activities in which a fin split is advantageous. In alternative aspects, fin blade 210 can include multiple fin splits. Moreover, as FIG. 2A illustrates fin ribs 220 a-220 b and foot pocket 230 are similar or identical to corresponding fin ribs 110 a-110 b and foot pocket 130 of FIG. 1A. Furthermore, as FIGS. 2B-2H illustrate, proximal indentations 217 a-217 b, distal indentations 218 a-218 b, distal protrusions 219 a-219 b, proximal protrusions 211 a-211 b, proximal indentation 215, and one or more sole treads 213 are similar or identical to corresponding proximal indentations 117 a-117 b, distal indentations 118 a-118 b, distal protrusions 119 a-119 b, proximal protrusions 111 a-111 b, proximal indentation 115, and one or more sole treads 113 of FIGS. 1B-1H. Regardless, FIGS. 2B-2H illustrate additional views of the split fin blade of the example swim fin shown in FIG. 2A. More specifically, the additional views shown in FIGS. 2B-2H illustrate features described in the foregoing discussion of FIGS. 1B-1H and 2A.

C. Example Adjustable Fin Blade

In general, FIG. 3A shows yet another example aspect of a modular and adjustable swim fin. More specifically, FIG. 3A shows a swim fin 300 that includes a fin blade 310, an adjustable fin split 312, fasteners 314 a-314 b, channels 316 a-316 b, fin ribs 320 a-320 b, and a foot pocket 330. Fin blade 310 with adjustable fin split 312 (located along the centerline of fin blade 310) provides improved versatility of the swim fin 300. In alternative aspects, fin blade 310 can include multiple fin splits, including fin splits like fin split 212, adjustable fin splits like adjustable fin split 312, or a combination thereof. Moreover, as FIG. 3A illustrates fin ribs 320 a-320 b and foot pocket 330 are similar or identical to corresponding fin ribs 110 a-110 b and foot pocket 130 of FIG. 1A. Furthermore, as FIGS. 3B-3H illustrate, proximal indentations 317 a-317 b, distal indentations 318 a-318 b, distal protrusions 319 a-319 b, proximal protrusions 311 a-311 b, proximal indentation 315, and one or more sole treads 313 are similar or identical to corresponding proximal indentations 117 a-117 b, distal indentations 118 a-118 b, distal protrusions 119 a-119 b, proximal protrusions 111 a-111 b, proximal indentation 115, and one or more sole treads 113 of FIGS. 1B-1H.

As FIG. 3A shows, fin blade 310 includes adjustable fin split 312. In some aspects, adjustable fin split 312 is a press seal (e.g., similar to the seals on resealable sandwich bags). In other aspects, adjustable fin split 312 is a zipper. In yet other aspects, adjustable fin split 312 can be any resealable fastener or closure for a seam or split. Additionally, FIG. 3A shows fin blade 310 includes fasteners 314 a-314 b which slide along channels 316 a-316 b respectively. When fasteners 314 a-314 b slide along channels 316 a-316 b to the centerline of fin blade 310 and adjustable fin split 312 is closed, then swim fin 300 is in a solid fin blade mode. Alternatively, when fasteners 314 a-314 b slide apart along channels 316 a-316 b away from the centerline of fin blade 310 and adjustable fin split 312 is open (i.e., split apart), then swim fin 300 is in a split fin blade mode. In the aspect shown in FIGS. 3a -3H, channels 316 a-316 b are on the top and bottom of the distal edge of fin blade 310. However, in other aspects, channels 316 a-316 b could be only on either the top or bottom of fin blade 310.

As shown in FIG. 3C, fin blade 310 includes closed protrusions 340 a-340 d and open protrusions 342 a-342 d. For example, fasteners 314 a-314 b pass over closed protrusions 340 a-340 d when they slide along channels 316 a-316 b to the centerline of fin blade 310. Accordingly, protrusions 340 a-340 d help to retain fasteners 314 a-314 b in a closed position. Along similar lines, fasteners 314 a-314 b pass over open protrusions 342 a-342 d when they slide apart along channels 316 a-316 b away from the centerline of fin blade 310. Thus, protrusions 342 a-342 d help to retain fasteners 314 a-314 b in an open position.

FIGS. 3D-3H illustrate additional views of the adjustable fin blade of the example swim fin shown in FIG. 3A. In particular, FIGS. 3D-3H show additional views of features described in the foregoing discussion of FIGS. 3A-3C.

The present invention may be implemented in other specific forms without departing from its spirit or essential characteristics. The described aspects are to be considered in all respects only as illustrative and not restrictive. The scope of the invention is, therefore, indicated by the appended claims rather than by the foregoing description. All changes which come within the meaning and range of equivalency of the claims are to be embraced within their scope. 

1. A modular swim fin comprising: an interchangeable foot pocket having an edge; an interchangeable fin rib having a proximal rib portion and a distal rib portion, the proximal rib portion shaped to overlap the edge of the interchangeable foot pocket; an interchangeable fin blade having a proximal indentation shaped to receive the edge of the interchangeable foot pocket and a distal indentation shaped to receive the distal rib portion of the interchangeable fin rib; a proximal fastener that secures the edge of the interchangeable foot pocket and the proximal rib portion of the interchangeable fin rib to the interchangeable fin blade; and a distal fastener that secures the distal rib portion of the interchangeable fin rib to the interchangeable fin blade.
 2. The modular swim fin as recited in claim 1, further comprising a rib aperture located on the distal rib portion of the interchangeable fin rib.
 3. The modular swim fin as recited in claim 2, further comprising: a proximal protrusion located on the bottom of the interchangeable fin blade, the proximal protrusion shaped to receive the proximal fastener; and a distal protrusion located on the bottom of the interchangeable fin blade, the distal protrusion shaped to receive the distal fastener.
 4. The modular swim fin as recited in claim 3, further comprising a sole tread located on the bottom of the interchangeable fin blade.
 5. The modular swim fin as recited in claim 4, wherein the interchangeable fin blade has a fin split.
 6. The modular swim fin as recited in claim 5, wherein the interchangeable fin blade has a curved distal edge and a distal portion that has a substantially concave top.
 7. A swim fin comprising: a foot pocket; a fin blade secured to the foot pocket; and an adjustable fin split operable to selectively configure the fin blade into either a solid fin blade mode or a split fin blade mode, the adjustable fin split located substantially at a distal end of the fin blade and along a centerline of the fin blade.
 8. The swim fin as recited in claim 7, wherein the adjustable fin split comprises a zipper.
 9. The swim fin as recited in claim 7, wherein the adjustable fin split comprises a press seal.
 10. The swim fin as recited in claim 7, further comprising: a channel located on a distal edge of the fin blade; a fastener slidably engaged with the channel; wherein when the fin blade is in the solid fin blade mode, the fastener slides towards the centerline of the fin blade, over a closed fastener protrusion, to secure the fastener in a closed position; and wherein when the fin blade is in a split fin blade mode, the fastener slides away from the centerline of the fin blade, over a open fastener protrusion, to secure the fastener in an open position.
 11. A method for improving the versatility of a swim fin comprising: providing a foot pocket; providing a fin blade secured to the foot pocket; and providing an adjustable fin split operable to selectively configure the fin blade into either a solid fin blade mode or a split fin blade mode, the adjustable fin split located substantially at a distal end of the fin blade and along a centerline of the fin blade.
 12. The method as recited in claim 11, further comprising providing one or more interchangeable fin ribs that attach to the fin blade to adjust the stiffness of the fin blade.
 13. (canceled) 